V. Reaction Rate (p. 532 - 541)

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V. Reaction Rate (p. 532 - 541)

• Ch. 17 Chemical Reactions

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A. Collision Theory

• Reaction rate depends on the collisions between
  reacting particles.
• Successful collisions occur if the particles...
• collide with each other
• have the correct orientation
• have enough kinetic energy to break bonds

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A. Collision Theory

• Particle Orientation

Required Orientation
Unsuccessful Collisions
Successful Collision
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A. Collision Theory

• Activation Energy (Ea)
• minimum energy required for a reaction to occur

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A. Collision Theory

• Activation Energy
• depends on reactants
• low Ea fast rxn rate

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B. Factors Affecting Rxn Rate

• Surface Area
• high SA fast rxn rate
• more opportunities for collisions
• Increase surface area by
• using smaller particles
• dissolving in water

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B. Factors Affecting Rxn Rate

• Concentration
• high conc fast rxn rate
• more opportunities for collisions

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B. Factors Affecting Rxn Rate

• Temperature
• high temp fast rxn rate
• high KE
• fast-moving particles
• more likely to reach activation energy

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B. Factors Affecting Rxn Rate

• Temperature
• Analogy 2-car collision

5 mph fender bender
50 mph high-speed crash
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B. Factors Affecting Rxn Rate

• Catalyst
• substance that increases rxn rate without being
  consumed in the rxn
• lowers the activation energy

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B. Factors Affecting Rxn Rate

• Enzyme Catalysis